Mercury Marine's Fuel Recommendations

Mercury Marine is a leading manufacturer of outboard engines and stern drives for boats. They maintain a section devoted to ethanol blended fuels on their website.

Some of the issues that I have seen discussed in the media latley with regards to ethanol's use in boats are addressed.

Are Mercury engines compatible with ethanol fuels?

The fuel-system components of Mercury engines will withstand up to 10 percent ethanol in gasoline - the maximum level currently allowed by the EPA in the U.S.

How does ethanol affect my fiberglass fuel tank?

Fiberglass tanks manufactured prior to 1991 may not be compatible with gasoline containing ethanol. It has been reported that, in the presence of ethanol, some resins may be drawn out of fiberglass and carried into the engine where severe damage could occur. If an older fiberglass tank is used, check with the manufacturer to determine if gasoline with ethanol can be safely used.

Are older fuel lines prone to failure? What about gaskets?

During the 1980s, many rubber components for use in fuel systems were developed to withstand exposure to fuels containing ethanol. If rubber components in a fuel system are suspected to be of this vintage or older it may be advisable to replace them with newer ethanol-safe components before using fuels containing ethanol. Check with the manufacturer for advice or frequently inspect these fuel-system components for signs of swelling or deterioration and replace if problems are noted.

Source : Mercury Marine